MAX6690 19-2190 Rev 2 4/09 2C Accurate Remote/Local Temperature Sensor with SMBus Serial Interface General Description Features The MAX6690 is a precise digital thermometer that High Accuracy 2C (max) from +70C to +100C (Remote) reports the temperature of both a remote P-N junction and its own die. The remote junction can be a diode-con- 11-Bit, 0.125C Resolution nected transistortypically a low-cost, easily mounted Dual Channel: Measures Remote and Local 2N3904 NPN type or 2N3906 PNP typethat replaces Temperature conventional thermistors or thermocouples. Remote No Calibration Required accuracy is 2C for multiple transistor manufacturers, Programmable Under/Overtemperature Alarms with no calibration needed. The remote junction can also 2 I C-Compatible/SMBus Interface be a common-collector PNP, such as a substrate PNP of +3V to +5.5V Supply Range a microprocessor (P). The 2-wire serial interface accepts standard System Ordering Information TM Management Bus (SMBus ), Write Byte, Read Byte, Send Byte, and Receive Byte commands to program the PART TEMP RANGE PIN-PACKAGE alarm thresholds and to read temperature data. MAX6690MEE -55C to +125C 16 QSOP Measurements can be done automatically and autonomously, with the conversion rate programmed by Typical Operating Circuit the user, or programmed to operate in a single-shot mode. The adjustable conversion rate allows the user to 0.1F 200 +3V TO +5V SUPPLY optimize supply current and temperature update rate to match system needs. When the conversion rate is faster than 1Hz, the conversion results are available as a 7-bit- 10k EACH CPU V STBY CC plus-sign byte with a 1C LSB. When the conversion rate MAX6690 is 1Hz or slower, the MAX6690 enters the extended DXP SMBCLK CLOCK mode. In this mode, 3 additional bits of temperature data are available in the extended resolution register, provid- SMBDATA DATA ing 10-bit-plus-sign resolution with a 0.125C LSB. DXN ALERT Single-shot conversions also have 0.125C per LSB reso- 2200pF INTERRUPT TO C lution when the conversion rate is 1Hz or slower. ADD0 ADD1 GND A parasitic resistance cancellation (PRC) mode can also be invoked for conversion rates of 1Hz or slower by set- ting bit 4 of the configuration register to 1. In PRC mode, the effect of series resistance on the leads of the external diode is canceled. The 11-bit conversion in PRC mode is Pin Configuration performed in < 500ms and is disabled for conversion rates faster than 1Hz. The one-shot conversion is also 11 TOP VIEW bits in < 500ms. N.C. 1 16 N.C. The MAX6690 default low-temperature measurement V 2 15 STBY CC limit is 0C. This can be extended to -64C by setting bit DXP 14 SMBCLK 3 5 of the configuration register to 1. DXN 4 MAX6690 13 N.C. The MAX6690 is available in a small, 16-pin QSOP sur- N.C. 5 12 SMBDATA face-mount package. ADD1 6 11 ALERT Applications GND 7 10 ADD0 Desktop Computers Workstations GND 8 9 N.C. Notebook Computers Test and Measurement QSOP Servers Multichip Modules Thin Clients SMBus is a trademark of Intel Corp. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.2C Accurate Remote/Local Temperature Sensor with SMBus Serial Interface ABSOLUTE MAXIMUM RATINGS (All voltages are referenced to GND unless otherwise noted.) Continuous Power Dissipation (T = +70C) A V ..........................................................................-0.3V to +6V 16-Pin QSOP (derate 8.30mW/C above +70C).........667mW CC DXP, ADD .................................................-0.3V to (V + 0.3V) Operating Temperature Range ........................-55C to +125C CC DXN ......................................................................-0.3V to +0.8V Junction Temperature......................................................+150C SMBCLK, SMBDATA, ALERT, STBY......................-0.3V to +6V Storage Temperature Range ............................-65C to +165C SMBDATA, ALERT Current .................................-1mA to +50mA Lead Temperature (soldering, 10s) .................................+300C DXN Current ......................................................................1mA ESD Protection (all pins, Human Body Model)................2000V Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = +3V to +5.5V, T = -55C to +125C, unless otherwise noted. Typical values are at V = +3.3V and T = +25C.) CC A CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS TEMPERATURE-TO-DIGITAL CONVERTER +60C T +100C, V = +3.3V -2.5 +2.5 A CC Accuracy (Local Sensor) 0C T +100C, V = +3.3V -3.5 +3.5 C A CC -55C T +120C, V = +3.3V -5.0 +5.0 A CC + 70 C T + 100 C , V = + 3.3V ( N ote 1) -2 +2 R J C C Accuracy (Remote Sensor) 0C T +100C, V = +3.3V (Note 1) -3.5 +3.5 C RJ CC - 55C T + 120C , V = + 3.3V ( Notes 1, 2) -5 +5 RJ C C Line Regulation 0.2 0.5 C +1 C Resolution (Legacy Mode) Conversion rate >1Hz +8 Bits +0.125 C Resolution (Extended Mode) Conversion rate 1Hz +11 Bits Undervoltage Lockout V input, disables A/D conversion, CC UVLO +2.60 +2.80 +2.95 V Threshold rising edge Undervoltage Lockout +90 mV Hysteresis Supply Voltage Range V +3.0 +5.5 V CC P ower - O n Reset (P O R) Thres hold V , falling edge +1.5 +2.0 +2.5 V CC POR Threshold Hysteresis +90 mV Standby Current SMBus static +3 +10 A Operating Current During conversion +0.55 +1 mA 0.25 conversion/s (Note 3) +40 +70 Average Operating Current A 2 conversion/s (Note 3) +150 +250 From stop bit to conversion completed, in Conversion Time t +95 +125 +156 ms CONV legacy mode (Note 3) Conversion Timing Error 25 % High level +80 +100 +120 Remote-Diode Current I A RJ Low level +8 +10 +12 2 MAX6690